Diffuser for paper machine headbox

ABSTRACT

A paper machine headbox of the type having a series of inlets is provided at each inlet with a conical diffuser to divert and diffuse the incoming stock flow. The several diffusers are mounted on a common shaft which is angularly adjustable to vary the orientation of the diffusers with respect to the inlets.

Mite States Patent 1 1 Kallmes et a1. Nov. 6, 1973 [5 1 DIFFUSER FOR PAPER MACHINE 2,156,445 5 1939 Baxter 162/343 HEADBOX 3,236,725 2/1966 Goldsmith 162/336 241,338 5/1881 Escoubes 292/265 Inventors: Otto J- Kallmes, Marblehead, Mass; 2,728,379 12/1955 Perry .1 292 265 f Rchland FOREIGN PATENTS OR APPLICATIONS 1 1 Assigneel f Paper cofnpafly, Division 0! 93,520 1/1959 Norway 162/341 Mllprmt, lnc., Mllwaukee, W1s. [22] Filed: Oct 18, 1971 Primary Examiner-Robert L. Lindsay, Jr.

Assistant Examiner-Richard V. Fisher PP N05 1901152 Attorney-Allan W. Leiser et al.

52 us. c1 162/341, 162/336, 162/343 1 1 ABSTRACT [51] Int. Cl. 1021f 1/06 A paper machine headbox of the type having a series [58] Field of Search 162/341, 216, 343, of inlets is provided at each inlet with a conical diffuser 162/336; 292/265, 266 to divert and diffuse the incoming stock flow. The several diffusers are mounted on a common shaft which is [56] References Cited angularly adjustable to vary the orientation of the diffusers with respect to the inlets.

4 Claims, 4 Drawing Figures PATENTED NOV 6 I975 INVEINTORS OTTO J. KALLMES RICHARD L. SADDLER BY I wflflw ATTORNEY DIFFUSER FOR PAPER MACHINE HEADBOX BACKGROUND OF THE INVENTION This invention relates to paper machine headboxes, and particularly to apparatus for diverting and diffusing stock flow through the headbox inlets.

Paper machine headboxes are conventionally provided with an inlet manifold which defines a series of inlets for the stock flowing into the headbox. In many cases, and notwithstanding the baffles and holey rolls or other obstacles the stock encounters in flowing through the headbox, there is a tendency for the streams issuing from the several inlets to maintain their integrity, thus resulting in streaks when the stock is deposited on the wire. Newer machines are provided with an increased number of inlets to minimize this problem, but converting to this type of construction is quite expensive and may still not eliminate streaking problems.

SUMMARY OF THE INVENTION It is the general object of this invention to provide diffusers to divert and diffuse flow through headbox inlets to eliminate streaking problems, and the invention is particularly suited but not limited to headboxes where there are relatively few inlets so that streaking would be more likely to be a problem. One specific object of the invention is to provide a conical diffuser which is highly effective in diffusing stock flow. Another specific object is to provide a diffuser which is angularly adjustable to meet varying siutations. Still an other specific object is to provide a series of diffusers for a series of inlets, with the several diffusers being adjustable in unison. Other objects and advantages will appear from the description to follow.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a partial schematic view showing a portion of a headbox and an inlet manifold for a paper machine, the headbox being provided with a series of diffusers to show a preferred embodiment of the invention,

FIG. 2 is a partial view in cross section through the plane 2-2 shown in FIG. 1,

FIG. 3 is a partial view in cross section through the plane 33 shown in FIG. 1, and

FIG. 4 is a partial view in cross section through the plane 4--4 shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing, the reference numeral 1 indicates a generally conventional paper machine headbox, and the numeral 2 refers to a conventional inlet manifold which is suitably supported and connected to the headbox 1. The manifold 2 includes a series of circular flow pipes 3 which extend through the wall of the headbox I and define circular inlets through which stock is admitted to the headbox l.

The flow pattern of the headbox l is shown by the arrows in FIG. 1. Stock moves horizontally to the left through the inlets 3, and is then turned vertically upwardly by a baffle wall 4. A holey roll 5 is disposed near the top of the baffle 4, and after passing the roll 5 the stock moves horizontally to the left. The headbox may contain more holey rolls or baffles as desired, and the stock is ultimately passed through a slice (not shown) onto a wire. The inlet manifold 2 is of course fed from a suitable source. Since the general construction of headboxes and inlet manifolds is well known to those skilled in the a111, and since the invention herein may be used with a variety of constructions, these elements are not shown and will not be described in further detail.

Disposed within the headbox l are a series of diffusers 6, with one diffuser 6 located in front of and in alignment with each inlet 3. The diffusers 6 are preferably of hollow, welded sheet metal construction, and are of essentially right circular conical configuration with the apex of each generally pointed toward the associated inlet 3. The apex and base of each diffuser 6 are preferably rounded off as shown to have an aerodynamic configuration. All of the diffusers'6 are fixed to a tubular shaft 7 which is rotatable for angular adjustment of the diffuser 6 as will be described.

In the preferred embodiment shown, the inlets 3 have an internal diameter of approximately nine inches and are spaced apart 16 inches on center. The shaft 7 has an external diameter of approximately 2 and inches, and its center line is spaced approximately 7 and 1% inches back from the vertical plane where the inlets 3 open into the headbox l. The diffusers6 have a maximum outside diameter of approximately 7 inches at the center line of the shaft 7, and extend from the center line of the shaft 7 toward the inlets 3 a distance of approximately 4 and 7s inches/The apex of each difiuser 6 is rounded off to form a spherical surface with a diameter of approximately 2 inches, and the conical surfaces between the apex and the center line of the shaft 7 have a taper of approximately 30. The base of each diffuser 6 is rounded off beginning at the center line of the shaft 7 on a radius of approximately 3 and inches. These dimensions have provided highly satisfactory results, but it will be obvious that there might be dimensional variations to fit particular requirements. Also, while the right circular conical configuration is preferred for use with circular inlets, other generally conical configurations might be used.

The shaft 7 extends through the several diffusers 6 and defines, for each diffuser 6, an axis of adjustment that is transverse to the central axis of the diffuser 6 and transverse to the associated inlet 3. The diffusers 6 are welded or otherwise suitably affixed to the shaft 7 in alignment with one another. The ends of the shaft 7 are mounted in suitable bearings 8, shown only schematically, which provide for rotation of the shaft 7 and prevent undesired longitudinal movement.

One end of the shaft 7, the lower end as seen in FIG. 2, extends entirely through the wall of the headbox l to present a stub 9. An actuating handle 10 is suitably fixed to the outer end of the stub 9 and provides for manual rotation of the shaft 7. As can be seen most clearly in FIG. 4, an L-shaped arm 11 is fixed to the back of the handle 10 and, with the handle 10, forms a channel which receives a circular curved track 12 which is mounted on the side of the headbox 1 by means of outwardly extending brackets 13, the radius point of the track E2 being at the center line of the shaft The track 12 is provided with a similarly curved line of holes 14, and the handle 10 and arm 11 are provided with aligned holes which are adapted to come into register with any of the holes 14 depending upon the position of angular adjustment of the shaft 7. A pin 15 is used to lock the handle 10 in any of the several possible selected positions and is itself locked in place by a cotter pin or other suitable means. While the adjustment and lock means shown and described is quite simple and highly effective, it will be obvious that other means might be used to accomplish the same purpose without departure from the spirit of the invention.

As seen in FIGS. 1 and 2, the diffusers 6 are in what can be termed a normal position in which their central axes are directly in line with the centers of the inlets 3, and the action of the diffusers in this position can be seen clearly by reference to FIG. 3. That is, stock flowing through the inlet 3 will come directly against the apex of the associated diffuser 6 and will tend to be spread approximately equally around 360, such diffusion serving to maintain the stock fibers in suspension and effectively destroy the integrity of the stream issuing through the inlet 3. While this action alone provides for excellent diffusion, it has been found advantageous in some situations to have the angular adjustability of the diffusers 6 afforded by the shaft 7 and its associated elements. The reason for this is not entirely clear, and the need for adjustability appears to depend upon many factors. Angular adjustment does, however, tend to change the diffusion pattern with advantageous results in certain situations. If, for example, the handle 10 is pivoted clockwise from the position shown in FIG. 1, there tends to be more lateral dispersion and less upward dispersion. If it is moved counterclockwise, there is also more lateral dispersion, but greater upward dispersion. As indicated, the choice of angular position may depend upon many factors, but a skilled paper machine operator will easily be able to select the position which provides the best results for any particular situation.

The preferred embodiment shown and described has given excellent results in preventing streaking, even in a machine with only eight inlets, which is a relatively small number. As indicated above, however, change in structure might very well be made without departure from the spirit and general concept of the invention. Accordingly, the invention is not intended to be limited by the showing or description herein, or in any other manner, except insofar as may specifically be required.

We claim:

1. In a paper machine headbox of the type having a plurality of horizontally oriented inlets arranged in a horizontal line, Y

a diffuser assembly comprising: rotatable shaft means in front of and at the level of and parallel to the line of inlets; a plurality of diffusers fixed to the shaft means, said diffusers being aligned with one another and with respective inlets, each difi'user being of substantially conical shape and having an apex which is rounded to form a generally spherical surface pointed generally toward its respective inlet, the shaft means defining a line extending through each difiuser transversely to the major central axis of the diffuser at a point spaced back from its apex; and adjustment means to rotate the shaft means through a substantial range of angular positions to thereby simultaneously and correspondingly adjust the orientations of the difiusers with respect to the inlets.

2. The combination of claim 1 wherein: there is a vertical baffle wall behind the shaft means and diffusers to turn stock flowing through the inlets upwardly.

3. The combination of claim 2 wherein: the diffusers are of substantially right circular conical configuration; and the inlets are of substantially circular cylindrical configuration.

4. The combination of claim 1 wherein: the base of each diffuser is rounded to form a generally spherical surface beginning approximately at the shaft line extending transversely through the diffuser. 

2. The combination of claim 1 wherein: there is a vertical baffle wall behind the shaft means and diffusers to turn stock flowing through the inlets upwardly.
 3. The combination of claim 2 wherein: the diffusers are of substantially right circular conical configuration; and the inlets are of substantially circular cylindrical configuration.
 4. The combination of claim 1 wherein: the base of each diffuser is rounded to form a generally spherical surface beginning approximately at the shaft line extending transversely through the diffuser. 